1st Biden-Trump debate: What time tonight and how to watch

When President Joe Biden and former President Donald Trump face off in Thursday's presidential debate, it will be a replay of 2020, but at the same time, much different now in 2024.

Hosted by CNN, the debate comes at a crucial time as undecided voters work to decide how to cast their ballots in what's expected to be a close contest in November. It's also an opportunity for Biden and Trump to highlight their competing visions for the United States should they become president.

It's the earliest-ever in a presidential race, taking place before the Republican and Democratic conventions in July and August -- when both Trump and Biden will officially accept their party's nominations.

The showdown is scheduled to go 90 minutes with two commercial breaks. There will be no live studio audience -- a major change from previous debates.

How to watch

CNN made the debate available to simulcast on additional broadcast and cable news networks in the U.S. and it will be simulcast on ABC and ABC News Live with pre-debate coverage beginning at 8 p.m. EDT on the network and 7 p.m EDT on ABCNL.

ABC News Digital and 538 will live blog the latest from the debate stage as it happens and provide analysis and the biggest takeaways from the night.

Moderated by CNN anchors Jake Tapper and Dana Bash, the debate will air Thursday, June 27 at 9 p.m. EDT/8 p.m. CDT/6 p.m. PDT.

It will air live on CNN, CNN International, CNN en Español, CNN Max and stream without a cable login necessary on CNN.com.

What are the ground rules?

CNN recently shared its rules for the debate, which both Biden and Trump agreed to.

Biden and Trump will stand at lecterns decided earlier by a coin flip. Their microphones will be muted unless it is a candidate's turn to speak, CNN said, which is likely to limit how much the candidates can interrupt each other.

Though it's yet not clear who will control the ability to mute the candidates' microphones, the moderators "will use all tools at their disposal to enforce timing and ensure a civilized discussion," according to the network.

According to CNN's rules, Biden and Trump won't be allowed to use any props or pre-written notes, but will be given paper, a pen and water. Their campaign staffs will not be allowed to interact with them during the debate.

To meet CNN's debate qualifications, candidates had to appear on enough state ballots to reach the 270 electoral vote threshold needed to win the presidency. Also, they must receive at least 15% in four separate national polls of registered or likely voters that meet CNN's standards for reporting.

CNN announced on Thursday that Biden and Trump met those requirements -- meaning third-party candidate Robert F. Kennedy Jr. won't make it on the stage.

What is the debate format?

The candidate will not give opening statements, CNN confirmed to ABC News.

They will each have two minutes to answer moderators' questions. They also will have one minute for rebuttals and responses to the rebuttals. Flashing red lights will warn them when they have five seconds left, and then turn solid red when their time has expired.

CNN has not yet given specifics about topics to be discussed.

How will this debate be different?

This isn't the first time Biden and Trump have squared off at a debate: The pair squared off twice during the 2020 election, but this time the circumstances are considerably different. Both now have one presidential term under their belts -- and several controversies as well.

This is Trump's first debate since he was found guilty of 34 felonies in his New York hush money criminal trial. In the run-up to this debate, it's something the Biden campaign has seized on through a $50 million advertising blitz, and many will be watching to see how Biden addresses Trump's conviction.

It is also unclear if Trump will bring up Hunter Biden, President Biden's son recently convicted on felony gun charges. Trump brought up Hunter Biden during their 2020 debate -- and has many times since then.

Biden's job approval rating will be ripe for Trump' attacks as well, with about 56% disapproving as of June 20, according to 538's polling average.

Trump will almost surely blame Biden for allowing a surge of migrants at the southern border, claim he's caused inflation and mismanaged foreign conflicts in Ukraine and Gaza .

In addition to Trump's conviction, Biden may hit Trump for his comments surround the Jan. 6 attacks at the U.S. Capitol.

Reproductive rights are another key issue for voters where Biden is likely to draw a comparison between his approach and Trump's. The former president has taken credit for the Supreme Court's June 2022 decision to overrule Roe v. Wade.

When is the next presidential debate? And what's next?

The June 27 debate marks the first of two debates Biden and Trump have agreed to. The second will be hosted by ABC News on Sept. 10.